In pneumopericardium, a rare but potentially life threatening condition, rapid diagnosis and adequate treatment is crucial. The etiologies of pneumopericardium can be classified into several groups. It can occur in all ages ranging from infants to adults. Acute hemodynamic deterioration should have prompt rapid further investigation and cardiac tamponade must be actively ruled out. We present the case of a infant who had respiratory distress syndrome, and had been subject to mechanical ventilatory assistance and later developed tension pneumopericardium and secondary tamponade. Emergent pericardiocentesis with hemodynamic monitoring did not result in a recovery. Usually, pneumopericardium is self-limiting requiring no specific therapy but clinicians should be familiar with this complication and prompt recognition with adequate treatment that may be life saving.

Pneumopericardium is a rare condition, less common then isolated either pneumothorax or pneumomediastinum. The characteristic symptoms are not always present and dependent on the extent of pneumopericardium and the underlining disease. Conventional chest radiographs, computed tomography, ultrasound, and echocardiography can confirm the diagnosis of pneumopericardium. Acute hemodynamic deterioration needs prompt further investigations and cardiac tamponade should be actively ruled out. In neonates and infants, usually positive pressure or in some cases, high frequency ventilation may cause pneumopericardium [21].

Case report

A newborn female was born prematurely on the 34th + 4/7 gestational week, vaginal delivery. The Apgar score was 8/9, the body parameters were: body mass of 3210g, length of 49 cm, and head circumference of 33 cm. The pregnancy was complicated by gestational diabetes and oligohydramnios. Due to the progression of respiratory distress and clinical signs the new-born was admited to the Neonatal Intensive Care unit 10 hours after birth.

The presentation of respiratory insufficiency and typical signs of respiratory distress syndrome (IV degree) led to the administration of a solution of natural surfactant (Curosurf) and artificial Intermittent Positive-Pressure Ventilation (IPPV). Hypoxia soon followed afterwards and the High Frequency Oscillation Ventilation (HFOV) was applied. At this time, there was a belief that the patient had a systemic infection due to the rise in C-reactive protein and the number of WBC that shifted to the left, even though the patient was receiving dual antibiotic therapy. On the fifth day, therapeutic conditions worsened with complications of right-sided pneumothorax. On the following day, the pneumothorax appeared on the left side as well (fig. a). The re-expansion of the lungs was maintained on the following days. Additionally, on the tenth day, thoracic drain worsened with complications of right-sided pneumothorax. On the following day, the pneumothorax appeared on the left side as well (fig. a). The re-expansion of the lungs was maintained on the following days. Additionally, on the tenth day, thoracic drain on the left side was withdrew and the reoccurring pneumothorax became complicated with pneumopericardium. Reinsertion of the drain resolved the intrathoracal free air, but pneumopericardium persisted and compromised the cardiac function (fig. b). X-rays showed reaccumulation of air in pericardium (fig. d). The employment of re-pericardiocentesis with negative pressure drainage (8 cm H2O) appeared to have adequately stabilized the deteriorating condition of the infant (fig. e). What appeared as a stable condition soon declined at a fast rate with crisis bradycardia and asystole. Although all procedures of cardiopulmonary reanimations were applied to stabilize the baby’s condition, the ending result was fatal.

On autopsy, the lungs of the patient were extremely underdeveloped with hyaline membrane formations confirmed serious respiratory distress syndrome (RDS). Bullous emphysema had been the main source of the long lasting pneumothorax. There had been consecutive accounts of bilateral bronchopneumonia and air tamponade of the heart were confirmed as well. According to the histological analysis, the main pathology had been diabetic fetopathy. In our case, excluding the statement above it was presented with hypertrophy and hyperplasia of the islets of Langerhans and increased body mass and length of the patient. The main cause of death might have been edema and hypoxia of the brain with internal hematocephalus and/or a septic condition with tamponade of the heart.

Figure a. Bilateral thoracic drainage

Figure b. Pneumopericardium

Figure c. After pneumopericardium drainage

Figure d. Reapparition of the pneumopericardium

Figure e. After the second drainage of the pneumopericardium

DiscussionBricheteau first described pneumopericardium in 1844 as a collection of air or gas forming between the pericardium and the heart [1, 2]. Pneumopericardium is an uncommon disorder that has been found in all age groups according to reported cases. In adults, pneumopericardium is most frequently caused by high velocity deceleration injuries and less commonly after falls from a height as an example [20]. In literature authors have described other causes of pneumopericardium such as spontaneous pneumopericardium, pulmonary inflammation, postoperative complications of thoracic surgery, and others listed in the appendix [4, 7] In infants, this condition is caused by mediastinal air dissecting at the reflection of the parietal to visceral pericardium near ostia of the pulmonary veins. The difference is probably due to the stronger adhesions between the pericardial layers in the adults, precluding the communication between the pericardial space and the mediastinum [3].

Many clinical signs of pneumopericardium such as radiation of pain towards the shoulders, the back, or the epigastrium are non-specific and unreliable. There may also be signs of dyspnea and precordial chest pain [8]. On the physical examination, distant heart sounds, and a succession of splashes with metallic tinkling referred to as “the mill wheel murmur” or “bruit de moulin” can be heard [1, 5, 8]. Sufficient accumulation of pericardial gas may impair right ventricular filling resulting in pericardial tamponade with increase and equalization of intracardiac pressures, pulsus s the shoulders, the back, or the epigastrium are non-specific and unreliable. There may also be signs of dyspnea and precordial chest pain [8]. On the physical examination, distant heart sounds, and a succession of splashes with metallic tinkling referredmetimes be heard as well [2, 8, 15].

A diagnosis can be usually made using X-rays, CT, and ultrasound [10]. Radiographically, pneumomediastinum and pneumopericardium are frequently confused since they can occur concomitantly. It is important to differentiate between these two. However, three signs on a chest radiograph are characteristic and can help in this differentiation. First, a radiolucent halo of air partially or completely surrounds the heart, but not extending superiorly to the attachments of the pericardium. Second, a shift in pericardial air on decubitus radiographs, and third, the absence of a continuous diaphragm sign [1, 3, 11]. In tension pneumopericardium the cardiothoracic ratio may decrease and the heart may appear extremely slender (small heart sign) [8]. A CT scan of the chest can reveal extensive bilateral airspace consolidation and the presence of a pneumopericardium, but no pneumomediastinum or pneumothorax. To discriminate air collections, CT surpasses echocardiography and MRI studies [13]. Echocardiography can help to diagnose pneumopericardium and provide guidance during needle aspiration. Relying on echocardiography is useful and may reveal pathognomonic spontaneous contrast within the pericardial space. Sometimes the features of cardiac tamponade are present. However, it may not always be readily available. Confirming the diagnosis by echocardiography following cardiovascular collapse may delay a definitive therapy [16]. In patients with pneumopericardium, electrocardiograph can typically show low voltage, ST segment changes, and T-wave inversion, but these are non-specific [1].

Treatment is immediately required if signs of tamponade are observed developing into a symptomatic pneumopericardium. This may include prompt needle aspiration when there is no communication between the pericardial sac and the pleural cavity, or an insertion of a tube for continuous pericardial drainage when there is a possible communication. According to some authors, it is necessary to perform a partial pericardiectomy to avoid recurrence and prevent pericardial constriction from reoccurring [1, 2]. In the absence of tamponade, pneumopericardium can probably be safely observed while treating the patient’s primary condition. This can include bed rest, observation, sedation, analgesics, antibiotics, and in ventilated patients a imperatively reduction of positive end-expiratory pressure (PEEP) and peak inflation pressure (PIP) [1].

Initially, needle aspiration of the pericardial sac should be performed to manage the acute episode and stabilize the patient, and then a 10 FR chest tube should be placed under direct vision into the pericardial sac and maintained on suction until positive end-expiratory pressure ventilation has been discontinued [14]. The standard technique used in the treatment of pneumopericardium begins with cleaning the skin over the xiphoid, precordium, and upper abdomen with alcohol. A 16, 18, or 20-gauge angiocath (1½ inch) attached to a 3-way stopcock and a 30 cc syringe is used [19]. The catheter is inserted 0.5 cm to the left of or just below the infant’s xiphoid, directing it toward left shoulder, aspirating with syringe as the catheter is advanced. A continuous suction via water seal system using 5-10 cm of H2O in the column is performed. A catheter position is confirmed by chest X-ray [9].

Insufficient surfactant causes respiratory failure in pre-term newborns. This disease is usually called Respiratory Distress Syndrome (RDS) or in some cases Infant respiratory distress syndrome (IRDS) [18]. Surfactant deficiency is accompanied by insufficient development of alveoli and leads to a decrease in lung compliance and poor ventilation-perfusion mismatch with resulting hypoxemia, hypercapnia, and increased respiratory effort. Respiratory distress syndrome affects 10% of all premature infants. Symptoms usually appear shortly after birth and become progressively more severe. Main risk factors are prematurity, diabetes mellitus in the mother, and perinatal asphyxia. The most frequent complications that occur spontaneously or as the result of well-intended therapeutic interventions are pulmonary air leaks-pneumothorax, but pneumomediastinum and pneumopericardium as well [18].

Since RDS usually occurs because of prematurity, prenatal administration of corticosteroids to the mother, two to three days prior to delivery may result in healthier babies. Beside surfactant therapy, most efforts at improving the therapy of respiratory failure have been concentrated on the modernizing and improvement of mechanical ventilation or new ventilatory techniques. All of these therapies are effective but not perfect, and the mortality rate from RDS and its complications is still meaningful [17].